TypeScript: a package's coverage script is preferred, but its LCOV is never read (0% in a nested package) #15

For a TypeScript package that is not the project root, typescript_command (src/crapper/runners.py:230) runs npm run coverage when the package defines that script. The report then lands where the script puts it: for Vitest, Jest, c8 and nyc that is <package>/coverage/lcov.info. But _lcov_paths (src/crapper/coverage.py:493) reads only <root>/target/coverage/**/lcov.info and <root>/coverage/**/lcov.info. So every function of the package scores 0%, and nothing is printed, because the command exited 0.

Without the script, crapper runs Vitest itself with --coverage.reportsDirectory=<root>/target/coverage/typescript/<slug> and scores correctly. Adding a coverage script, which --help lists as the first TypeScript strategy, therefore makes coverage disappear in a monorepo.

A root without package.json, and a package app/:

app/package.json   "scripts": { "test": "vitest", "coverage": "vitest run --coverage --coverage.reporter=lcov" }
                   devDependencies: vitest 5.0.1, @vitest/coverage-v8 5.0.1
app/src/sum.ts     export function sum(values: number[]): number { … }   (CC 3)
app/src/sum.test.ts  one test covering every line

From the root:

crapper app/src/sum.ts

+ (…/repro/app) npm run coverage
> vitest run --coverage --coverage.reporter=lcov
sum                            sum                                    3   0.0%     12.0

app/coverage/lcov.info exists and covers src/sum.ts fully. With the coverage script removed, the same command runs

+ (…/repro/app) …/app/node_modules/.bin/vitest run --coverage --coverage.reporter=lcov --coverage.reportsDirectory=…/repro/target/coverage/typescript/app --coverage.reportOnFailure=true --coverage.include=src/sum.ts
sum                            sum                                    3 100.0%      3.0

A related silent 0%: with a plain "coverage": "vitest run --coverage", Vitest's default reporters (text, html, clover, json) write no LCOV at all, and crapper again reports 0% without a word.

Suggestions, any of them would help:

• after npm run coverage in a package, also read <package>/coverage/**/lcov.info, with its paths relative to the package, as for the report crapper writes itself;
• when the package uses Vitest, run Vitest directly even if a coverage script exists, keeping npm run coverage for other runners;
• warn, or exit non-zero, when the coverage command succeeded but no LCOV was found for the package.

Environment: Linux x86_64, Node 23.5.0, npm 11.11.1, Vitest 5.0.1, crapper 6fd92c4.